It's a rather exhaustive line of merch, normally reserved for the likes of enduring cultural icons or the latest mega-selling pop sensations. Yet, while devotees will need little introduction to the otherworldly terrors of the mythos, the uninitiated will no doubt be scratching their heads and wondering who is this Cthulhu, and how has his cult suddenly become so all pervasive?

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn.

"In his house at R'lyeh, dead Cthulhu waits dreaming."

The Call of Cthulhu, HP Lovecraft

Great Cthulhu first appeared in The Call of Cthulhu, published in Weird Tales magazine in 1928 and his name has become a kind shorthand for a style of wildly imaginative style of horror, which sees mankind as a small insignificant footnote, in a cold, hostile and extremely unforgiving universe.

This space is peopled by dark, unknowable gods, cruel alien races and bizarre, malevolent creatures, who view mankind as at best, an army of potential slaves, at worst, a ready supply of fresh sustenance. It is said Dread Cthulhu himself will one day rise from his sleep to enslave mankind beneath his yoke, but for the moment he lies dreaming in the undersea city of R'yleh, 'until the stars align’.

Cthulhu and the entire mythos was the invention of Howard Phillips Lovecraft, an American horror author of the 1920s and '30s who was virtually unknown in his own lifetime, save for appearances in classic pulp magazines like Weird Tales. Shy, introverted and something of a night bird, since his death, Lovecraft's influence has spread like the tentacles of his most memorable creation, to permeate popular literature, movies, comics and wider culture.

How did such an obscure figure rise to exert "an incalculable influence on succeeding generations of writers of horror fiction" as Joyce Carol Oates once observed? Well, as someone who has some distinctly Lovecraftian influences pervading his own work, there's a number of answers to that intriguing question.

"The oldest and strongest emotion of mankind is fear. And the oldest and strongest kind of fear is fear of the unknown."

HP Lovecraft

Although he was an admirer of Edgar Allan Poe and produced plenty of conventional horror fiction too, Lovecraft's third phase of writing, his 'mythos period', is unique, innovative and bears little relation to earlier conceptions of horror. Other writers borrow liberally from myth and legend, but Lovecraft's mythos is sui generis, in a class all of its own. There really was nothing like it before, though there's been plenty since.

Lovecraft's central idea of mankind alone, vulnerable and unprotected in a bleak, antagonistic and ultimately meaningless universe, where we are prey to the whims of powerful, unknowable and alien entities is really one of the starkest and most terrifying kinds of horror. All humanity's hopes, beliefs, emotions and systems count for nothing in the vast alien indifference of this universe. It's known as cosmic horror for a very good reason.

An artist's impression of Shub-Niggurath. Used here with permission from Matt Dixon

As well as this fantastically original conception, Lovecraft populated his creation with a whole pantheon of alien beings like Hastur: He Who Is Not to be Named, Yog-Sothoth and Shub-Niggurath – The Black Goat with a Thousand Young (and if those names alone, don't leave you asking for more I don't know what will). Lovecraft also created the town Arkham (familiar, Batman fans?) and the Miskatonic university and chronicled the dark cults of men who worship those foul entities, and the bookish heroes who are sometimes able to succeed in delaying their inevitable triumph. You can also can also 'thank' Lovecraft for a whole library of forbidden texts like the Necronomicon, the book of the dead, the reading of which plunges men's mind into insanity and death. That's quite a net contribution to the historical roll call of horror, you have to concede.

A Legacy of Horror

Yet while Lovecraft remained largely unknown in his lifetime, he was a dedicated and prolific correspondent and was in a regular touch with a circle of influential writers, many of whom adopted his ideas wholesale or used important elements of it, always with his blessing. Lovecraft was a generous writer and made his creation virtually open source, positively encouraging others to borrow liberally from his ideas.

Lovecraftian influences appear in writers like Robert E. Howard, inventor of brooding Cimmerian Conan, Fritz Leiber of Fafhrd and the Grey Mouser fame, and even Robert Bloch's Psycho. After his death, his friend August Derleth posthumously published Lovecraft's collected works and expanded his universe even further, bringing it to a wider audience and shaping the mythos as we know it today.

The Lovecraft Reader

So should you take a plunge into this world of cosmic terror? Absolutely. Pick up the complete works on Kindle for under a quid (!) and dive on in. Lovecraft's prose can be convoluted and his attitudes to race, gender, ethnicity and class do jar with modern sensibilities. But he was a man of his time and they can largely be forgiven for the majesty of the ideas.

Start with the great four: At the Mountains of Madness, Shadows Over Innsmouth, The Dunwich Horror and of course The Call of Cthulhu itself. Then revel in The Rats In the Walls, The Case of Charles Dexter Ward, The Colour Out of Space, Pickman's Model and The Tomb. Virtually any Lovecraft story is worth reading if you're a fan of macabre tales and want to feel delicious thrills of terror slowly creep up your spine.

Cthulhu Now

Stephen King called Lovecraft "the Twentieth century's greatest practitioner of the classic horror tale" and his influence on modern fiction remains profound. King, William Burroughs and Neil Gaiman are stellar talents who recognise their debt to Lovecraft and you can read his continuing influence in modern masters of the macabre like David J Rodger's classic sci-fi and dark fantasy series. It'd probably remiss of me not mention my own humble effort, The Seraph Chronicles, which sees one man dare to oppose Dread Cthulhu and his minions down the ages (for a free sample, see below).

On the big screen, Giger, John Carpenter, Guillermo del Toro and the entire Evil Dead saga are just a few to proudly display their Lovecraftian influences on their sleeves. Superb graphic novels like Alan Moore's Neonomicon, Grant Morrison's Zenith and Mike Mignola's Hellboy also bow down before Lovecraft's dread altar and games like Call of Cthulhu, Acthung!, Cthulhu and Yellow Dawn of Hastur, allow you to experience his visions in all their dark glory.

Even now, nearly 30 years after my first reading, I still find Lovecraft fascinating and return to re-read them once in a while. The pure originality of his work, the central terrifying concept of cosmic horror and the unique generosity of his open-source approach has allowed his creation to not only survive, but flourish and his legacy in the pantheon of horror greats is assured.

So next time you see a tentacled Cthulhu plushie, perhaps spare a small thought for Howard Phillips Lovecraft, and reflect on how the inventions of one rather obscure early 20th century American author's mind, have risen to run like a seam through vast swathes of modern horror fiction, movies and culture. Still dreaming in his vast undersea tomb, Dread Cthulhu himself will no doubt one day wake and find, to his surprise, that he appears to have already conquered this world in absentia.

Gizmodo Readers' Offer!

If you'd like a free copy of John Houlihan's first Cthulhu influenced Seraph adventure, The Trellborg Monstrosities, for Kindle or Kindle app just mail jollybigpublishing@gmail.com and mention Gizmodo. John is also happy to hear from readers, writers and fellow sci-fi, fantasy and literary enthusiasts.

Biography

John Houlihan has been a writer, journalist and broadcaster for over 25 years, for many publications including The Times, Sunday Times and Cricinfo. He is a former editor-in-chief of Computer and Video Games.com. For latest news and information see www.John-Houlihan.net or follow @johnh259 on Twitter. You can see his work on the Amazon Store

Later this year he will publish the next Seraph novel, Before The Flood, and he is editor of Dark Tales from the Secret War, a World War 2 Cthulhu-influenced short story collection due to be published later this year.